Globular Cluster Photo Series (Part 20): M14

Today I have a picture of the globular cluster Messier 14 in Ophiuchus. M14 is a rather large cluster around 100 light-years across, and at a respectable distance of about 30,300 light-years. The cluster's large physical size gives it a size of 11.0 arcminutes on the sky, about a third the width of the full Moon. The entire cluster shines about 400,000 times as bright as the Sun, but is just below naked-eye visibility at its distance.

Messier 14 in Ophiuchus.

M14 is known to contain 70 variable stars, quite a decent number for a globular cluster. In 1938 a nova went off in the cluster, but this fact was not discovered for 28 years until photos of the cluster taken in 1938 were examined in 1964. It's estimated from these photos that the nova reached a peak brightness over 5 times that of the brightest non-nova stars in the cluster. This is only the second nova known to have appeared in a globular cluster (and the first was in 1860, before it could be photographed).